FIG. 1.

Individual chromosomes condense into a single SAHF focus. (A) Chromosome (Chr.) 4 painting combined with cyclin A2 gene fluorescence in situ hybridization (FISH) in growing and senescent WI38 cells. DNA was stained using DAPI. (B) Chromosome 6 and X chromosome painting and DAPI staining of senescent WI38 cells. Images were collected by confocal microscopy. (C) Senescent WI38 cells were stained with DAPI to visualize DNA (blue) and with ACA to visualize kinetochore proteins bound to centromeric DNA (red).